1. Field of the Invention
The invention relates in general to a paper-separating plate with multi-stages. More particularly, the invention relates to a paper-separating plate suitable for a paper-seized mechanism of an automatic document feeder (ADF).
2. Description of the Related Art
An image input/output device, such as a copying machine, a facsimile machine or a scanner, is provided with an image-input system. In general, a document is placed on a glass plate, and an optical system placed under the glass plate is used to read an image, such as words or figures. In case the dimensions of documents coincide, the image input/output device can be designed with an automatic document feeder matching the optical system. Therefore, by the automatic document feeder, the documents can be transferred one by one and pass by the surface of the glass plate. Meanwhile, the images of the documents can be read by the linear scanning of the optical system. Also, the automatic document feeder can be mounted on a printer or other machines where a stake of documents has to separates.
Currently, the automatic document feeder is provided with the paper-separating mechanism in order to transfer documents one by one to a scanning region of the optical system of the image input/output device. FIG. 1 is a cross-sectional view showing a known traditional paper-separating mechanism. A paper-separating mechanism 100 includes a paper-separating roller 110, a paper-feed roller 120 and a paper-separating plate 130. The paper-separating roller 110 and the paper-feed roller 120 are mounted in the automatic document feeder. The axis of the paper-separating roller 100 is substantially parallel with that of the paper-feed roller 120 and the rolling direction of the paper-separating roller 110 is the same as that of the paper-feed roller 120. Besides, the contact surface 132 of the paper-separating plate 130 is elastically pressed onto the bottom surface of both the paper-separating roller 110 and the paper-feed roller 120. For example, one end of the paper-separating plate 130 is pivoted on the automatic document feeder, as shown in the right portion of FIG. 1, while a spring 134 is mounted onto the other end of the paper-separating plate 130, as shown in the left portion of FIG. 1. As a result, the contact surface 132 of the paper-separating plate 130 can be elastically pressed onto the bottom surface of both the paper-separating roller 110 and the paper-feed roller 120.
The condition that documents 10 are separated by the paper-separating mechanism 100 is that the friction (Fr) between the roller (the paper-separating roller 110 or the paper-feed roller 120) and documents 10 is larger than the friction (Fp) between the paper-separating plate 130 and documents 10 and that the friction (Fp) between the paper-separating plate 130 and documents 10 is larger that the friction (Fd) between documents 10. In other words, the condition that documents 10 are separated by the paper-separating mechanism 100 is xe2x80x9cFr greater than Fp greater than Fdxe2x80x9d. When a stack of documents 10 is transferred into the paper-separating mechanism 100, a first paper-separating operation is performed using the paper-feed roller 120 and the paper-separating plate 130. In an ideal case, documents 10 should be transferred one by one to the space between the paper-separating roller 110 and the paper-separating plate 130 using the paper-feed roller 120 and the paper-separating plate 130. However, two or three sheets of documents 10 may be transferred to the space between the paper-separating roller 110 and the paper-separating plate 130. In the case, several sheets of documents 10 are first separated from a stack of documents 10 using the paper-feed roller 120 and the paper-separating plate 130. Subsequently, the several sheets of documents 10 first separated are transferred to the space between the paper-separating roller 110 and the paper-separating plate 130. Next, only one sheet of documents 10 is second separated from the several sheets of documents 10 first separated using the paper-separating roller 110 and the paper-separating plate 130. However, provided that the condition of xe2x80x9cFr greater than Fp greater than Fdxe2x80x9d is not satisfied, two or even more sheets of documents 10 can be output after documents 10 are separated using the paper-separating roller 110 of paper-separating mechanism 100 and the paper-separating plate 130. The documents 10 can not be separated one by one effectively.
Accordingly, an objective of the present invention is to provide a paper-separating plate with multi-stages. The paper-separating plate with multi-stages is suitable for a paper-separating mechanism. The paper-separating effect with multi-stages is provided using the paper-separating plate of the invention so that the success probability of separating documents one by one is enhanced.
To achieve the foregoing and other objectives, the present invention provides a paper-separating plate adapted for a paper-separating mechanism having a paper-separating roller. The paper-separating plate placed around a side of the paper-separating roller comprises a main body and a cushion. The main body has a surface and a plurality of grooves and the grooves are positioned on the surface. The cushion is positioned on the surface of the main body and covers the grooves. The cushion positioned over the partial grooves is elastically pressed onto the paper-separating roller. The grooves linearly extend in a direction substantially parallel with the axis of the paper-separating roller, the linear grooves neighboring one another or each other. Besides, the cushion is made of flexible material and the main body is made of rigid material.
Both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention, as claimed. It is to be understood that both the foregoing general description and the following detailed description are exemplary, and are intended to provide further explanation of the invention as claimed.